UNEP/EUROBATS

Agreement on the Conservation of Populations
of European Bats

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Autumn bat migration season has started, time to get ring recoveries!

Favorable weather conditions have encouraged millions of bats to migrate from north-eastern Europe to their wintering areas in Germany, France, Italy, the Benelux and probably other countries.

More than 5,000 bats have already been ringed at the ornithological station in Pape / Latvia in August 2016. Bats were captured in a Heligoland trap, which is operated by a cooperation between the Leibniz institute for Zoo and Wildlife Research (IZW) in Berlin and the Latvian University in Riga.

Heligoland trap at Pape (Latvia). Photo: Jasja Dekker

According to Prof. Dr. Gunars Petersons (Agricultural University Jelgava) more than 4,000 ringed Nathusius bats (Pipistrellus nathusii) were released since the beginning of the migration season at the Latvian Baltic coast on the 19th of August 2016, as well as several Soprano pipistrelles (Pipistrellus pygmaeus), Parti-coloured bats (Vespertilio murinus) and common noctules (Nyctalus noctula). The results of this year represent a new record for the research station in Pape, which carries out bat research since the 1960s. Attending bat researchers from Latvia, Germany and the Netherlands were amazed by the unique natural spectacle, as thousands of bats were flying along the coastal migration corridor.

Also in Saxony-Anhalt (Federal state in Germany) first migration movements were registered. “For several days, the Nathusius bats, Parti-coloured bats and Leisler’s bats have been migrating with great intensity”, says Bernd Ohlendorf from the state's reference Centre for Bat Conservation. Here, in cooperation with the local bat working group (Arbeitskreis Fledermäuse Sachsen-Anhalt e.V.), some 4,000 Nathusius bats, Parti-coloured bats and Leisler’s bats (Nyctalus leislerii) were ringed since spring 2015.

For effective conservation of bats, it is necessary, inter alia, to identify migration routes, roosting sites, resting and wintering areas by ring-recaptures, because "concerning bat migration, we are groping in the dark," says Christian Voigt, scientist at the IZW. "Only a few recoveries and acoustic studies suggest the real extent of the autumnal migration movements. The number and the range of the annual trails surpass everything that is known about mammals. Even the migratory herds of wildebeest in the Serengeti do not move such long distances", says Christian Voigt.

Since the start of autumn migration, first fatalities at wind turbines have already be seen. In a wind farm in Lithuania 7 dead Nathusius bats were found in a single sporadic inspection. In Saxony-Anhalt a ringed noctule was found, dead beneath a wind turbine. According to IZW, bats are dying by collisions and even due to the enormous pressure fluctuations caused by the rotating blades (barotrauma).